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Providing perspectives on recent research into vitamins and nutritionals


Looking for Information on Dietary Assessment for Research? Look Here!

By Julia Bird

One of the great pillars of nutrition science is the estimation of nutrient intakes in populations. If we don’t know what people are eating, we can’t discover associations between nutrients and health. But, there are a great deal of different methods for estimating the nutritional content of people’s diets. How does one choose the best method? Ultimately, the choice of dietary assessment tool comes down to the primary research question, and the resources available. The method chosen should ideally at least meet a minimum standard to enable researchers to fully address their nutrition query. However, practical and financial limits are normally set on the collection of data, therefore  it is good to know when a particular assessment tool is more than adequate.

To help researchers with the selection of the most appropriate way to measure dietary intakes, the National Cancer Institute has developed a Dietary Assessment Primer. This resource contains all the information that nutrition researchers need to select the correct dietary assessment tool. All estimates of diet are prone to both error and bias, and the primer contains complete information on the methods available, their advantages, and drawbacks. A good place to start is the Roadmap: this page contains links to the background information about dietary assessment instruments, descriptions of the tools available, key concepts in nutritional epidemiology, and a full reference list to allow researchers to look into the details behind the tools presented in the primer.

The recommendations of the best tool to use are contained in the summary table. Depending on the research that is planned and the endpoints of interest, researchers can look up the best tool to use. For example, if researchers want to describe the mean usual intake of a nutrient in a group, they are recommended to use a single 24-hour dietary recall from each participant. The use of a food frequency questionnaire is possible, and multiple 24-hour dietary recalls are more than necessary. However, when researchers are interested in calculating the difference between proportions of two groups consuming a nutrient above or below a certain threshold, they are better off using multiple 24-hour dietary recalls, although a single dietary recall may be acceptable in a large population, or food diaries may be possible if they are calibrated to the dietary recall. By using this table, researchers can quickly determine whether the tool they intend to use is acceptable or not.

Extensive background information in the “Learn more” section, a glossary, and references are also provided to complete the information. This primer contains all important information on dietary assessment in one place, as well as useful links to reliable resources to help researchers select the correct tool. This primer will certainly help improve the quality of nutrition research!


Main citation:

Thompson, Frances E. et al. The National Cancer Institute’s Dietary Assessment Primer: A Resource for Diet Research. Journal of the Academy of Nutrition and Dietetics. Published Online: September 29, 2015